def add(a,b):
    result = a + b
    return result

r = add(1,2)
print(r)


def say_hi():
    print("你好呀")
r = say_hi()
print(f"无返回值函数，返回的内容是{r}")
print(f"无返回值函数，返回的内容类型是{type(r)}")


def check_age(age):
    if age>18:
        return "SUCCESS"
    else:
        return None
result = check_age(16)
if not result:
    print("未成年，不可进入")